1. Field of the Invention
The present invention relates to devices for aligning rail mounted cars, carriages, or equipment with track-side structures, and in particular, with devices for aligning certain coke oven auxiliary equipment with coke oven doors.
2. Description of the Prior Art
On the completion of the coking process it is conventionally the practice to remove a pair of doors from the opposite sides of a coke oven and to extend a pusher ram into the oven from its pusher side so as to push the coke contained therein into a quenching car positioned adjacent to the coke side of the oven. Included in the equipment necessary to carry out such a pushing operation is the abovementioned pusher ram as well as door extractor rams and jamb cleaners for the doors on both sides of the oven. These items of equipment, which will be collectively referred to, herein, as "auxiliary equipment", are typically mounted on cars which move on rails along the sides of the coke oven. The cars are stopped alongside a particular door and the abovementioned items of auxiliary equipment are, at the appropriate time during the pushing procedure, projected toward the door so as to perform their particular functions.
While this positioning would seem simple enough in principle, it is important that it be carried out with a certain degree of precision since even a small error in the positioning of a car relative to a coke oven door might result in damage to the door, the oven, or the auxiliary equipment, itself, when a misaligned item of auxiliary equipment is projected with force toward the door. Because it is often difficult for an operator to visually judge with sufficient precision when a car has been properly positioned, various devices have been developed for the purpose of indicating when alignment is correct. U.S. Pat. No. 3,451,898, for example, discloses an aligning device in which a rod, having a terminal fork that is engageable with the door frame, is mounted parallel with a door extractor ram and is moved forward toward the door with, but somewhat ahead of, the door extractor ram. In this device two limit switches are arranged in parallel such that the rear section of the rod opens one switch as the rod begins to be advanced toward the door. If alignment is correct, the rod will proceed forward until the fork engages and becomes fully seated on the door frame and a trip on the rod closes the second limit switch so that current to the door extractor ram's drive motor is not interrupted. If, however, alignment is not correct, the fork will not become seated on the door frame and the rod will consequently be prevented from proceeding far enough forward so that the second limit switch will not be closed, and current to the door extractor ram drive motor will be interrupted. The misaligned door extractor ram will, accordingly, be prevented from proceeding further toward the door.
While the device described above appears to accurately indicate whether a door extractor ram is aligned with a coke oven door, its use may be somewhat time consuming since it requires that the relatively slow moving extractor ram be moved forward with the indicator rod. Furthermore, after alignment has been completed, the usual procedure for employing this device would appear to require that the indicator rod remain in a forward and seated position on the door frame while the door extractor is in use. Because the indicator rod is so exposed, the possibility exists that it would be damaged during the pushing operation. It is, therefore, the object of the present invention to provide a device which quickly indicates whether a piece of projectable auxiliary equipment is aligned with a coke oven door without actually having to move such equipment toward the door. It is a further object of the present invention to provide an aligning device which has a minimal risk of being damaged during the coke pushing procedure.